How can French Muslims participate -- assimilate -- in a Republican system that is by constitution secular without themselves falling into apostasy, which is unacceptable to them?
I'm quite unable to address all the complexities of this problem, or maybe even some of its basics. But one possible answer from a jurisprudential perspective for Muslims might partly depend on how one understands the contours of
dar al' amm. If Muslims can be allowed to peaceably live in a country where they are not prevented from practicing Islam, then those schools of jurisprudence that recognized this category of the "house of safety" would expect Muslims who lived in such a place to in turn be law-abiding citizens of the country that gave them such protections. But then the tricky issue would be identifying what constitutes the practice of Islam. Certainly the freedom of religious association and expression would be required to meet the standards of
dar al' amm, but if those requirements included the wearing of certain kinds of apparel, ect., then the problem becomes thornier, and presents a challenge to non-Mulsim countries to accommodate the needs of believers. Obviously, the relevant issues go far beyond the confines of mere jurisprudence and involve ethnicity, historical factors, social tensions and so on. But there are at least recognizable and precedented religious grounds for Muslims not to be pressed into choosing between fidelity to Sharia and religious struggle.